Athletes have no excuse on doping: Grace

There is "no excuse" for athletes not knowing what is going into their bodies, the lawyer representing Essendon players and head of Athletics Australia says.

David Grace QC said the zero tolerance model was the best way to stamp out drugs in sport.

"As I stand here today, there is no excuse for any athlete to take a substance without being 100 per cent sure that that substance is approved and is not contrary to any anti-doping policy," Mr Grace told a sport conference in Melbourne on Friday.

"If there is reliance upon doctors or medical personnel, then it's incumbent upon the organisation involved to ensure that those medical personnel are versed in what they need to do to ensure that any substances that are taken are not infringing the anti-doping policy."

Mr Grace is president of Athletics Australia, as well as representing 34 present and former AFL players in a Federal Court action between Essendon and the Australian Sports Anti-Doping Authority.

Mr Grace said he did not want to comment on the Essendon situation specifically as it was still "fluid".

He said ASADA was doing a good job in its policing of drug cheating in Australian sport, but with more resources it could do a better job in grassroots education.

"In terms of its general policing for drug detection amongst athletes I think it does a good job," Mr Grace said.

Justice John Middleton has reserved his decision in a Federal Court case over whether ASADA and the AFL's investigation of Essendon was lawful.